How can I work with binary messages

You've 3 options

1. convert the binary message into XML
2. use an attachment to hold the message and have an empty XML document for the content of the message
3. convert some key pieces of information from the binary message into a small XML document that can be used for content based XPath routing while keeping the binary attachment around in case you need it

Any of those 3 options are fine. Clearly 1 provides the maximum amount of reuse of ServiceMix/JBI components like BPEL, XPath routing, XSLT transformation, XQuery support and so forth - whereas there is little the JBI services can do with binary messages other than just pass them along.

So the choice of 1, 2 or 3 depends on how much services you need & how much information you need to be accessible in the message